Search results
Results from the WOW.Com Content Network
Compound eye of a house centipede Compound eye of a dragonfly. A compound eye is a visual organ found in arthropods such as insects and crustaceans.It may consist of thousands of ommatidia, [1] which are tiny independent photoreception units that consist of a cornea, lens, and photoreceptor cells which distinguish brightness and color.
In bees, locusts, and dragonflies, the lens is strongly curved; while in cockroaches it is flat. Locusts possess vitreous humour while blowflies and dragonflies do not. Two somewhat unusual features of ocelli are particularly notable and generally common between insect orders.
The angle between adjacent rhabdomeres within a single ommatidium (the acceptance angle) is similar to the angle between adjacent ommatidia (the inter-ommatidial angle), giving the eye a continuous field of view with areas of overlap between neighboring ommatidia; [2]: 161–2 the advantage of this arrangement is that the same visual axis is ...
The labium is just visible from the side, between the front pairs of legs. The role of the labium in some insects, however, is adapted to special functions; perhaps the most dramatic example is in the jaws of the nymphs of the Odonata, the dragonflies and damselflies. In these insects, the labium folds neatly beneath the head and thorax, but ...
Most arthropods have at least one of two types of eye: lateral compound eyes, and smaller median ocelli, which are simple eyes. [2] When both are present, the two eye types are used in concert because each has its own advantage. [3] Some insect larvae, e.g., caterpillars, have a different type of simple eye known as stemmata.
A World War I British P Helmet, c. 1915 Zelinsky–Kummant protivogaz, designed in 1915, was one of the first modern-type full-head protection gas masks with a detachable filter and eyelet glasses, shown here worn by U.S. Army soldier (USAWC photo) Indian muleteers and mule wearing gas masks, France, February 21, 1940 A Polish SzM-41M KF gas mask, used from the 1950s through to the 1980s
PureWow editors select every item that appears on this page, and the company may earn compensation through affiliate links within the story. You can learn more about that process here. Yahoo Inc ...
Here, the vertex, or the apex (dorsal region), is situated between the compound eyes of insects with hypognathous and opisthognathous heads. In prognathous insects, the vertex is not found between the compound eyes, but rather where the ocelli are normally found. This is because the primary axis of the head is rotated 90° to become parallel to ...